Pension Plans and Other Postretirement Benefits Components of Pension and Postretirement Benefits Expense (Details) - USD ($) $ in Thousands				12 Months Ended
	Jan. 01, 2018	Jan. 01, 2017	Jan. 01, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted-average assumption percentages:
Expected return on plan assets	6.73%	6.73%	6.85%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost				$ 117	$ 121	$ 115
Interest cost				2,168	2,340	2,483
Expected return on assets				(7)	(110)	(187)
Actuarial loss (gain)				(5,400)	2,014	1,275
Amortization of prior service benefit				(48)	(95)	(95)
Total net pension benefits cost (credit)				$ (3,170)	$ 4,270	$ 3,591
Weighted-average assumption percentages:
Discount rate				3.99%	4.35%	4.59%
Discount rate				4.55%	3.99%
Expected return on plan assets				7.00%	7.00%	7.00%
Rate of compensation increase				3.50%	3.50%	3.50%
Pension Plans
Weighted-average assumption percentages:
Net pension or postretirement benefits credit						$ 10,800
U.S. Plans | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost				$ 1,043	$ 985	1,028
Interest cost				26,804	28,614	30,514
Expected return on assets				(38,621)	(36,243)	(36,445)
Actuarial loss (gain)				30,234	(13,910)	5,988
Amortization of prior service benefit				60	75	75
Total net pension benefits cost (credit)				$ 19,520	$ (20,479)	$ 1,160
Weighted-average assumption percentages:
Discount rate						4.67%
Discount rate				4.59%	4.03%	4.43%	4.67%
Expected return on plan assets				6.89%	6.89%	6.89%
Rate of compensation increase				0.00%	0.00%	0.00%
Foreign Plans | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost				$ 3,919	$ 2,547	$ 3,133
Interest cost				5,144	5,128	6,570
Expected return on assets				(4,204)	(4,441)	(4,027)
Actuarial loss (gain)				(10,833)	483	19,418
Amortization of prior service benefit				34	56	859
Total net pension benefits cost (credit)				$ (5,940)	$ 3,773	$ 25,953
Weighted-average assumption percentages:
Discount rate						2.76%
Discount rate				2.15%	1.94%	2.00%	2.76%
Expected return on plan assets				5.52%	6.16%	6.66%
Rate of compensation increase				3.18%	3.18%	3.16%